verdant tumbleweed

Tumbleweed is not notably verdant. In its most distinctive form, the tumbling tumbleweed, it is not verdant at all.

Tumbleweed is not notably productive.

It is difficult to make sense of this simile. On its own, it might be ironic, but this reading would make the sentence contradict itself. As this is one of three sentences that explain the criteria for awarding the literary prize, an internally inconsistent assertion is unexpected.